A significant literature exists on strategies for producing polymer nanoparticles. For example, when an amphiphilic polymer is present in a solvent at a concentration above its critical micellar concentration, it will self-assemble into nanoparticle structures. Even when such a polymer is present at a lower concentration, it can be caused to form nanoparticles by decreasing the solvation of the solvent such as by diluting the solvent with water. Solvents that have traditionally been used to manufacture nanoparticles were usually one or more of dimethyl sulfoxide (DMSO), dimethyl acetimide, dimethyl formamide, chloroform, tetramethyl formamide. Unfortunately, each of these is highly toxic and expensive.
In addition to the fact that they require one or more toxic solvents, standard methods for generating polymer nanoparticles tend to be slow (requiring up to several days to complete nanoparticle assembly), and to give only low yields of nanoparticles. Thus, the cost of the components, the speed and yield of the chemical reaction, the toxicity of the residual components, and the overall expense of the available processes for producing nanoparticles can have a profound negative impact on the commercial feasibility of using such nanoparticles.
Nanoparticles are often proposed for use as a delivery mechanism for a biologically active agent, such as a pharmaceutical. Frequently, it has been challenging to incorporate (or “load”) the biologically active agent into the nanoparticle because the amount that can be incorporated is limited or that it takes a great deal of time to incorporate the material (through, for example, diffusion). This challenge can limit the practical or commercial utility of the nanoparticle as a delivery mechanism for a biologically active agent.
Therefore, there is a need for the development of inexpensive, efficient methods of manufacturing nanoparticles. There is a further need for the development of methods of manufacturing nanoparticles that do not utilize or leave behind toxic residual components or reaction by-products.